1. Field of the Invention
The present invention relates to a vacuum insulated switchgear, specifically, to a technology for suppressing dielectric breakdown of a vacuum insulated switchgear that uses a solid insulation method.
2. Description of Related Art
A power receiving facility has a closed power distribution panel (referred to below as a switchgear at appropriate places) that includes a vacuum breaker for shutting off load current and fault current, a disconnecting switch and an earthing switch for securing safety for an operator who services a load, a detector for detecting a voltage and current in the system, a protective relay, and the like.
This type of switchgear is insulated in various ways; in addition to conventional air insulated panels and cubicle gas insulated switchgears (GISs) that use an SF6 gas, switchgears that use solid insulation, compressed air insulation, and complete vacuum insulation have come on the market in recent years as an aid to solving environmental issues.
For example, Patent Document 1 describes a vacuum insulated switchgear in which a switching portion that integrates shutoff, disconnection, and earthing functions into a vacuum container is solid-insulated by being molded by epoxy resin, and a conductor on a bus side and conductor on a load side that extend from the switching are solid-insulated.    Patent Document 1: Japanese Patent Laid-open No. 2007-14087